text: If the gene in question is the wildtype a superscript + sign is used:
  *leuA
  If a gene is mutant, it is signified by a superscript -:
  *leuA
  By convention, if neither is used, it is considered to be mutant.
  There are additional superscripts and subscripts which provide more information about the mutation:
  * = temperature sensitive (leuA)
  * = cold sensitive (leuA)
  * = amber mutation (leuA)
  * = umber (opal) mutation (leuA)
  * = ochre mutation (leuA)
  * = resistant (Rif)
  Other modifiers:
  *Δ = deletion (ΔleuA)
  *- = fusion (leuA-lacZ)
  * = fusion (leuA:lacZ)
  * = insertion (leuA::Tn10)
  *Ω = a genetic construct introduced by a two-point crossover (ΩleuA)
  *Δdeleted gene::replacing gene = deletion with replacement (ΔleuA::nptII(Kan) indicates that the leuA gene has been deleted and replaced with the gene for neomycin phosphotransferase, which confers kanamycin-resistance, as oftentimes parenthetically noted for drug-resistance markers)